Wireless communication devices, such as cellular telephones, have proven very popular in the Untied States, as well as in other countries. The operating characteristics of such cellular telephones are often tailored to accommodate the habits of the cellular telephone's principal user. For example, a complex telephone that is capable of recognizing spoken commands may be trained to the speech patterns of a particular user. Once determined through training, the pattern-recognition parameters needed to interpret that user's speech are typically stored by the telephone in nonvolatile memory. Because the telephone's speech recognition capability enables a vehicle's driver to operate the telephone with minimal distraction, such a telephone is convenient for use in an automobile and therefore increasingly important in the marketplace. Other cellular telephones might offer an internal telephone book or speed-dial list, which would be set to reflect the preferences and needs of a single user and, once set, are stored in nonvolatile memory.
In general, the two exemplar telephones mentioned above are responsive to the market for single-user cellular telephone terminals. Although the commercial success of cellular telephony speaks well for the utility of such designs, the single-user philosophy has clear disadvantages.
To clarify this point, consider circumstances wherein a cellular telephone is permanently integrated into an automobile, or wherein a telephone is used to provide a radio frequency (RF) link for a stationary or fixed cellular terminal such as a single-line terminal (SLT) or multi-line terminal (MLT) intended to serve a population of rural users, or wherein a handheld cellular telephone is shared among several users, for example among parents and children. In these circumstances, the limitations of the single-user approach become inconveniently evident: speech recognition parameters, speeddialers, telephone books, billing records, and other information tailored to a particular user and held in nonvolatile memory must be frequently reestablished and reentered as the telephone is used by different people.
In response to such limitations, cellular telephones that operate according to the GSM standard provide for the optional use of subscriber information module (SIM) cards. SIM cards, briefly put, enable cellular users to carry their identities from telephone to telephone. For example, PCT application WO 96/21327 shows the use of a SIM card to tailor the operation of a fixed cellular terminal. Inserting a SIM card into an SLT or MLT host tailors the billing and account information of that host to the identity of a particular user.
Although a SIM card provides useful options, the SIM card nevertheless has its own disadvantages. A user must remember to carry a SIM card from place to place in order to gain its benefits. This is both an inconvenience and a risk, as the user may be caught without a SIM card when it is needed, and the card itself may be lost. Moreover, the functions supported by current SIM cards are quite limited, and do not include, for example, the transfer of speech-recognition parameters.
Along a different vein, European Patent Application EP 0 730 387 A2 proposes the nonvolatile storage of a plurality of telephone books and a plurality of number address modules (NAM), so that a particular telephone book is associated with a particular NAM. With this invention, a given handheld telephone can support multiple service subscriptions (NAMs), for example a business subscription and a personal subscription. A different telephone book is associated with each subscription, with the provision of re-associating the subscriptions and telephone books by keyboard-and-menu intervention. However, each telephone book is associated with a service subscription or telephone number rather than with the identity of a particular user of the telephone.
All told, the method of operation suggested by the above-named European Application is once again a reflection of the single-user philosophy--it does not provide conveniently tailored features for a telephone that is used by more than one person but served by a single subscription. For example, it does not well serve the needs of a family that shares an automobile with an integrated cellular telephone and a single service subscription that is used by a number of different drivers and passengers. In these circumstances, it is often desirable to have only one service subscription and telephone number associated with the automobile, in order to save the cost of multiple service subscriptions, or to economize by bundling minutes-of-use under one telephone number so as to enter a favorable region of a communications tariff, or to avoid the need to dial multiple numbers to reach the automobile when the exact identity of its driver is unknown to the calling party. Moreover, the functions supported by the above-named European Application are again quite limited, and do not explicitly include anything beyond the selection of telephone books.
It is further known to limit the access of communication devices to communications service by means of passwords. Typically, a password is a numerical sequence comprising at least four digits so as to minimize the likelihood that an unauthorized user might guess the proper sequence. To gain access, a prospective user enters a password by keyboard. This entry is compared with an earlier-entered password reference stored in the communication device's nonvolatile memory. If the entry and the reference match, the communication device grants access to the prospective user; otherwise, the prospective user remains locked out. Once the password is successfully entered, various options and subscriptions may be available to that user according to the methods proposed by the above-named European Patent Application. No privacy is accorded to these options by today's methods, however, once general access is granted. Moreover, the user must laboriously select the appropriate options from a list of possibilities by further manual intervention.
In view of the limitations of the approaches outlined above, there remains a need for a simple, convenient, transparent way of enabling a communication device to support the preferences of a multiplicity of end users while operating under one or more service subscriptions. More particularly, there remains a need for a way of identifying a particular end user of a communication device rather than the identity of a service subscription, and based on the user's identity, of automatically tailoring the communication device to suit the user's preferences, all the while preserving the freedom of service under one service subscription and telephone number as well as under a plurality of subscriptions and telephone numbers.